.product-imgs{
  padding: 40px 20px 27px;
  display: flex;
  flex-wrap: wrap;/*自动换行*/
  justify-content: space-around;
}
.product-imgs li{
  flex: 0 0 280px;
  margin-bottom: 40px;
  position: relative;
}
.product-imgs li a{
  font-size: 14px;
  color: #ffffff;
}
.product-imgs li .pro-title{
  width: 100%;
  height: 30px;
  line-height: 30px;
  display: block;
  background-color: rgba(0,0,0,.5);
  text-align: center;
  position: absolute;
  bottom: 0;
}
.product-imgs li:hover{
  box-shadow: 2px 2px 3px #01a1ff,  -2px -2px 3px #01a1ff;
}
.product-imgs li:hover .pro-title{
  background-color: #01a1ff;
  opacity: 1;
}